If the place states dogs are welcome, those of you who don't like dogs indoors have an easy choice, don't go in. Those of us who want/have to keep our dogs with us will obviously choose establishments that welcome dogs. I know, I've already posted similar comments but it really isn't complicated.
Dogs who are taken about with their people are rarely smelly or badly behaved because they'll be bathed, groomed, trained properly . Like Anja I have never ever seen a dog eating from a plate of human food.
Another issue is that many holiday lets that take dogs, do not want the dogs left alone in the accommodation. British weather isn't always conducive to sitting outside whilst you eat.